This application relates to a field programmable radio frequency communications systems and more particularly to field programmable digital intermediate frequency (IF) demodulator and modulator circuits and signal processing circuits therefor.
Descriptions of the various components of the system are contained in co-pending patent applications owned by the assignee hereof and filed concurrently herewith, specifically: U.S. patent application Ser. No. 09/184,714, entitled xe2x80x9cReconfigurable Radio System Architecture And Method Therefor now U.S. Pat. No. 6,091,765xe2x80x9d; U.S. patent application Ser. No. 09/184,716, entitled xe2x80x9cA Control System For Controlling the Processing Data of a First In First Out Memory and Method Thereforxe2x80x9d; U.S. patent application Ser. No. 09/184,940, entitled xe2x80x9cConfigurable Circuits for Field Programmable Radio Frequency Communications Equipment and Methods Thereforxe2x80x9d; U.S. patent application Ser. No. 09/184,710, entitled xe2x80x9cA System For Accelerating the Reconfiguration of a Transceiver and Method Thereforxe2x80x9d; U.S. patent application Ser. No. 09/184,711, entitled xe2x80x9cA Field Programmable Modulator-Demodulator Arrangement For Radio Frequency Communications Equipment, And Method Thereforxe2x80x9d; U.S. patent application Ser. No. 09/184,708, entitled xe2x80x9cA Digital Noise Blanker For Communications Systems And Methods Therefor, now U.S. Pat. No. 6,292,654xe2x80x9c; U.S. patent application Ser. No. 09/184,712, entitled xe2x80x9cTCM Revisiting System and Methodxe2x80x9d; U.S. patent application Ser. No. 09/184,941, entitled xe2x80x9cLeast Squares Phase Fit As Frequency Estimatexe2x80x9d; U.S. patent application Ser. No. 09/184,715, entitled xe2x80x9cPolar Computation of Branch Metrics For TCMxe2x80x9d; U.S. patent application Ser. No. 09/184,746, entitled xe2x80x9cEfficient Modified Viterbi Decoderxe2x80x9d, now U.S. Pat. No. 6,289,487; U.S. patent application Ser. No. 09/184,713, entitled xe2x80x9cReceiver For a Reconfigurable Radio System and Method Thereforexe2x80x9d; each of which is incorporated herein by reference.
In the use of radio frequency equipment for communications, there is a need for a large a variety of types communication devices, such as receivers, transmitters and transceivers that are able to operate with a large variety of communications schemes, or waveforms such as, AM, AME, A3E, H3E, J3E, CW, SSB, M-PSK, QAM, ASK, angular modulation, including FM, PM, FSK, CMP, MSK, CPFSK etc., as well a need of being able to process the signals within the communications devices, such as by filtering, gain control, impulse noise rejection, etc. To acheive this in the past, a plurality of different dedicated pieces of equipment was required, such as, receivers, transmitters and transceivers, each designed to operate with separate communication schemes or waveforms, or a limited group of schemes or waveforms. Hence it would be desirous to have a configurable type of radio frequency communications equipment that is readily field programmable to function as a transmitter and receiver and to be able to be programmed to function with any of the above mentioned communications schemes or waveforms.
An important building block for a configurable type transceiver is a configurable digital intermediate frequency (IF) transmitter and receiver signal processing circuit that can be field programmed to provide the receiver demodulation functions and transmitter modulator functions and also corresponding waveform filtering and shaping. Hence, it would be desirous to have a digital IF demodulator and modulator circuits that is field programmable to operate with a large variety types of communications schemes, or waveforms such as, AM, AME, A3E, H3E, J3E, CW, SSB, M-PSK, QAM, ASK, angular modulation, including FM, PM, FSK, CMP, MSK, CPFSK etc. Further, there are times when multiple types of outputs are desirous from such circuits, such as cartesian and polar, for the same signal scheme or waveform. Hence, it would be desirous if a field programmable digital baseband signal processing circuit would be provided that would programmable to function with a variety of signaling schemes or waveforms and that could provide multiple outputs for signaling schemes.
In the addition, quite often there is a need for portable battery operated radio frequency communication equipment. Hence it is desirous with battery operated type of equipment to make the equipment as small and as light as practical for ease of handling, and to reduce the power drain on the equipment battery to extend the portable life of the equipment.
Is therefor an object of this invention to provide a new and improved field programmable digital IF signal processing system for radio frequency communications equipment that can be readily configured by the user in the field as functioning as either a receiver or transmitter signal processing circuit.
Is also an object of this invention to provide a new and improved field programmable digital IF signal processing system for radio frequency communications equipment that can be readily configured by the user in the field to operate with any of a plurality of communications schemes or waveforms.
Is also an object of this invention to provide a new and improved field programmable digital IF signal processing system for radio frequency communications equipment that can be readily configured by the user in the field to operate in any of a plurality of communications schemes or waveforms and configured to provide filtering and wave shaping parameters in accordance with the selected communications scheme or waveform.
Is also an object of this invention to provide a new and improved field programmable digital IF signal processing system for radio frequency communications equipment that can provide multiple types of signal outputs for a variety of signal schemes or waveforms.
Is also an object of this invention to provide a new and improved field programmable digital IF signal processing system for radio frequency communications equipment field that is relatively light weight for portable equipment.
Is also an object of this invention to provide a new and improved field programmable IF signal processing system for radio frequency communications equipment that is designed to use reduced battery power to extend the life of the portable mode of operation.
These and other objects and advantages of the present invention will be readily apparent to one skilled in the art to which the invention pertains form a perusal of the claims, the appended drawings, and the following detailed description of the preferred embodiments.